I have a similar issue with an old FP website. Will follow this thread and try some of the ideas here. Thanks and Good Luck.
WordPress or another CMS (content management system) although WordPress is the easiest Full Featured CMS. There are others and some are even easier for those not looking for as many bells and whistles. http://get-simple.info/ is one that doesn’t require a database
Both of the above and in fact, most CMSs allow pasting/inputting html directly into the editor which would make it pretty easy to transfer your content over. You can also paste formatted content(copy from front end) and it will pick up on the html tags so your headings remain headings, lists remain lists etc.
Front Page is the worst for outputting clean html. If you want to use something similar, find an older copy of dreamweaver. Much cleaner code, easy to use, has ftp connection to upload your files/site.You can pick up dreamweaver 3 or 4 on ebay for cheap. iirc, dreamweaver will clean up front page code pretty well.
pm me if you have any questions on the above